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Topic: New aircraft (Read 11994 times)

Having been away from home for a few days without access to my usual development computer, I cannot easily work on the code, but I have been able to work on the pakset. I have found a number of online sources of free 3-d models of aircraft whose licenses permit their use in at least non-commercial games (there are a variety of licenses: I link to the original file in the relevant .dat file). Some of the licences allow redistribution of the models themselves (which I am uploading to Github now, which should help people who want to produce additional aircraft from them), but some only permit redistribution of the rendered images, which will not be uploaded. I am somewhat hampered working on my Linux machine in that it is not compatible with Sketchup in which a lot of the free models are produced, and most of the automatic conversions to Collada or similar formats on the websites are broken (sometimes missing textures, sometimes missing parts, sometimes being entirely blank). I might be able to get further with that when I get back to my Windows computer at home, although I expect that I will need to prioritise the coding by then.

In any event, here is an overview of some of the new aircraft.

A Junkers F.13

A Boeing 274 and a Beech Model 18

A De Havilland Albatross

A Boeing 307 Stratoliner

A Boeing 737-100

A Boeing 737-300

A Boeing 787-8

A De Havilland Canada 3 "Otter"

An Embraerar ERJ-145

A Vickers Vanguard (cargo version depicted; passenger version also available)

A Vickers VC-10 (standard version depicted; super version also available)

Aero Commander 680 and Dornier 228

A comparison of the size of the Boeing 737-100, 737-900ER and 787-8.

There are a few others, not pictured, such as the Junkers W34, Lockheed Vega and De Havilland Dragon Rapide. With the exception of the Vanguard and VC-10, I have not added multiple liveries for these, as texturing is quite a substantial amount of work compared to converting them for use in Simutrans; however, for those who would like to create multiple liveries for these, I have uploaded as many of the models as permissible to the Blender Github repository.

I should note that the whole pakset is open source (using the Artistic Licence 1.0), and many of the .blend files used to create the objects are also available (sadly, not all of the aircraft), so you and anyone else are free to modify any of them as you please without asking first.

If you do produce modified versions, I should be very grateful if you could upload them (including sources) for everyone to enjoy, although this is not compulsory provided that you comply with the terms of the Artistic Licence 1.0.

I must confess that I cannot take much of the credit for this, as these are all models freely available to download from various sources online whose licences are compatible with the rendered images being used for Simutrans, and the only work that I have done is to adapt them for Simutrans, render them and to write the .dat files.

Unfortunately, many of the licences are not compatible with the models themselves being made available, although some of them are, and those are available on the Github repository.

Thank you for the offer of assistance. What sort of balancing had you in mind? Prices and costs I am not concerned with at present because those will need to be rebalanced from scratch using real life data when I have completed a minimum set of balancability features.

For the other attributes, such as the passenger/cargo capacity, takeoff/landing runway lengths, ranges, etc., I have tried to find real life data for this where possible (and note that, for passenger capacity, I am working on a new feature, on the passenger-and-mail-classes branch of both pakset and main code to have separate capacities for separate classes of passenger/mail, which I have implemented on that branch for aircraft as well as updating slightly some of the aircraft on the master branch), but if you believe that you are able to find better data than I have been able to find, then I should appreciate any correction. I have left, I think, quite a few comments in the code indicating where I found the data and in some cases at least where I have had to make an educated guess.

I would like to focus on the technical data, let me make some examples: in my aircraft the range, weight, and load capacity are calculated on the aircraft data and considering the fuel tank halfway.Length of the takeoff track is calculated at 0 meters above sea level and 20 degrees centigrade.The turbofan engine power is calculated by means of a "homemade" formula as there is no way to calculate the one in function of the other.

With regard to prices and costs, I am not the most suitable person for the calculation.

If you would like to calibrate the range, power, minimum runway length, etc. to be consistent with your aircraft, then, yes, please do; that would be helpful. Thank you. (Please do check the passenger-and-mail-classes branch to check that you have not missed any as there are a number of extra versions, mostly high and low density variants).

Or you may use the Junker F13 (fe variant) (mail and passenger) (introduced 1928):Power 205kW (motor has 228kW but there are losses in the trasmission, water pump, alternate....).Cruise speed 170km/hTractive effort 3kNWeight 1600kgPayload 600kgRange 950km

Actually I don't have access to github, could you update data in github?

Splendid, thank you for that. I have updated this (using the 1920 version) to use your statistics, although I am not sure what to do with the payload for mail/passengers, as the capacity for neither tends to depend on volume rather than weight, so I have left the capacities as they were before.

The payload is the maximum allowable, for each airplane there is in fact the parameter MTOW (max take off weight) and OEW (operational empty weight). The sum of the weight of: petrol, passengers, luggage, cargo (let's call it total load) can not exceed the difference between MTOW and OEW or the plane could not take off.

There are therefore two limits, one imposed by weight and one by volume, neither of the two can be overcome.

For passengers, there is usually a fixed number of seats that someone has calculated on the basis of what the aircraft can sensibly carry, so one can just refer to information about the number of seats for that. For mail, however, I am not sure how to calculate a payload taking into account both volume and weight.

Very little data for the Junkers W34.Power 298kWTractive effort 4kNWeight 1900kgOther data are correct.(I will not have access to github for a rather long time ... please update data)

Mail: The mail has a low weight / volume ratio because it is "light" compared to other materials. I saw very little information on the internal cargo volume of the aircraft. I think the only thing to do is to consider only the weight limit without evaluating the limit on the volume.

Splendid - now incorporated. I have left the mail capacity alone at present, as I suspect that a capacity based solely on weight would yield far too high a capacity. The best thing to do is find some known values for aircraft mail capacities (I think that I managed to find one for a DC-3 once) and extrapolate from those.

I have verified that the specific weight of the paper is 0.7-1.15 kg / dm3 (that is between 700 and 1150 kg / m3). Let's assume that the mail has a specific weight three times less in the case that the envelopes are ordered and ten times lower in case of messy envelopes.The loocked vega has a maximum load of 600kg, which equates to about 1.8 m3 in the case of tidy envelopes or 6 m3 in the case of messy envelopes.Starting from this example, can we consider that weight is more limiting than volume?

I have verified that the specific weight of the paper is 0.7-1.15 kg / dm3 (that is between 700 and 1150 kg / m3). Let's assume that the mail has a specific weight three times less in the case that the envelopes are ordered and ten times lower in case of messy envelopes.The loocked vega has a maximum load of 600kg, which equates to about 1.8 m3 in the case of tidy envelopes or 6 m3 in the case of messy envelopes.Starting from this example, can we consider that weight is more limiting than volume?

Giuseppe

I think that it is very difficult to say without having some actual data on aircraft mail capacity.